A dark thriller about an unhappy Barcelona apartment-block concierge set on destroying the happiness of others, "Sleep Tight" is designed to give auds sleepless nights, and mostly succeeds.

A dark thriller about an unhappy Barcelona apartment-block concierge set on destroying the happiness of others, “Sleep Tight” is designed to give auds sleepless nights, and mostly succeeds. Featuring a shudder-inducing perf from Luis Tosar, pic reps a worthy addition to the eminently marketable canon of recent Spanish horror, as helmer Jaume Balaguero capably handles a more classical approach to genre than the mock-doc technique deployed for the “Rec” gorefests he co-helmed. Good opening-weekend B.O. in Spain should be followed by solid sales offshore.

Right from the start, it’s clear that Cesar’s (Tosar) obsession with happy-go-lucky Clara (Marta Etura) will end badly. Clara’s perpetual radiance frustrates the beetle-browed Cesar, who considers himself incapable of such joy.

Cesar has clearly failed charm school. The tactics he employs to upset Clara include sending disturbing anonymous letters, entering her apartment at night to inject her skin cream with a liquid that will give her welts, and lying under her bed while she sleeps before quietly giving her chloroform and sliding in between the sheets. But preteen neighbor Ursula (Iris Almeida) is up to Cesar’s tricks, and starts blackmailing him.

During the daytime, Cesar musters all the sweetness and light he can, taking care of the dogs owned by elderly resident Veronica (Petra Martinez). But after he releases about a kilo of roaches into Clara’s apartment, she leaves the building, which was not his intention. After she returns with boyfriend Marcos (Alberto San Juan), an even angrier Cesar ups the stakes.

Tosar, having delivered the most memorably over-the-top psycho perf in recent Spanish cinema in Daniel Monzon’s “Cell 211,” here shows he can embody a whole different register of sociopath. Fawning, mumbling and humble by day, Cesar at night becomes as quick, dark and morally oblivious as the roaches he’s let loose; Tosar’s intensely compelling perf is at times more disquieting than the fast-moving plotline can handle.

Though it would be overstating things to say the script generates sympathy for Cesar, it is careful in the early scenes to show his cruelty as pathetically childish. Pic’s centerpiece is a scene that elegantly straddles farce and horror as Cesar is trapped in Clara’s apartment with Clara and Marcos. It’s testament to the skill of scribe Alberto Marini (adapting his own novel) that viewers will find themselves, hopefully uncomfortably, rooting for the villain. Indeed, Tosar’s perf is sufficiently gripping to paper over some credibility flaws, mostly deriving from the incredible good luck Cesar seems to have when executing his admittedly meticulously laid plans.

Etura (also a “Cell 211″ vet) does decent work, but is hampered by the fact that Clara is passive and fundamentally uninteresting. The clumsiest scenes have Cesar confessing to his hospitalized mother (Margarita Roset) — unnecessary given pic employs voiceover.

Like the two “Rec” films released so far, “Sleep Tight” is set mostly within a single apartment block, and Pablo Rossi’s lensing turns its old, creaking elevators and shadowy nooks and crannies into an appropriately Gothic backdrop that juxtaposes nicely with the clear pastels and streaming sunlight of Clara’s apartment. Extensive use of closeups makes for some creepily textured images and intensifies the general sense of claustrophobia.

Patti Page’s 1955 hit “Keep Me in Mind” is used in a couple of sequences, somewhat unsubtly illustrating the truism that love is a dangerously obsessive game.

Sleep Tight

Spain

Production

A Filmax release of a Filmax Entertainment presentation of a Castelao Producciones production with the participation of TVE, Canal Plus, TVC. (International sales: Filmax, Barcelona.) Produced by Julio Fernandez. Executive producers, Carlos Fernandez, Alberto Marini. Directed by Jaume Balaguero. Screenplay, Alberto Marini, based on his novel.